The present invention relates to lamp electrode orientation and, more particularly, the present invention relates to a method and apparatus for transporting and orienting electrodes for a lamp.
It is common in the prior art to use vibratory feeders to transport electrodes used in lamps from a supply of electrodes to a desired location. Prior art vibratory feeders include a vibratory bowl having an internal track that extends around the inner surface of the vibratory bowl from a base of the vibratory bowl to a top of the vibratory bowl. The internal track of the vibratory bowl transports electrodes from the base of the vibratory bowl to the top of the vibratory bowl. Some prior art vibratory feeders also include an external track that extends from an end of the internal track at the top of the vibratory bowl to the location where the electrodes are to be transported.
The external track includes a horizontal or vertical slot that is sized to accept electrode shanks. The electrode shanks slide into the slot in the external track. As the external track vibrates, a coil portion of the electrode tip moves along the slotted external track with the shank portion following in the slot. Irregularities in the shank portion and the coil portion frequently cause electrodes to get jammed in the slot of the external track. Electrodes frequently get caught in the slot of the prior art feeder causing jams. Jams are also caused by debris that enters the slot, such as broken or loose electrode tips, incorrect electrodes, clumps of emission powder and other foreign material.
It is desirable to recycle electrodes that are not successfully welded during lamp assembly. Unsuccessful welding of an electrode increases the size of the electrode shank. If used in a prior art slot-type feeder, the increase in size of the shank of an unsuccessfully welded electrode would prevent the shank from entering the slot or would cause the shank to become lodged in the slot. Recycled electrodes cannot be used in prior art feeders, because the shank will not enter the slot, or will become jammed as a result of the enlarged shank will becoming xe2x80x9cwedgedxe2x80x9d in the slot of the external track.
Prior art vibratory feeders vibrate continuously. The electrode moves continuously along the internal and external tracks to a gating system. The prior art gating system employs plungers that move up and down to allow individual electrodes to exit the external track. The plungers are timed such that a preceding plunger rises at the same time a following plunger moves downward to intercept and stop a next subsequent electrode. Since the electrodes do not always move at the same rate along the external track, the cylindrical plunger often moves down onto an electrode causing a jam of the gating system which jams the entire vibratory feeder.
The present invention concerns a method and apparatus for transporting and orienting electrodes for assembly into a lamp. The apparatus for transporting and orienting electrode tips includes a vibratory bowl having an outlet for supplying electrodes to a vibratory track. The vibratory track has a first end that is in communication with the outlet of the vibratory bowl. One or more gradually inclining wall portions are included in the vibratory track. The one or more gradually inclining wall portions are adapted to engage shank portions of misoriented electrodes to reorient the electrode tips.
The electrode transporting and orienting apparatus may also include an air jet mounted near the vibratory track for applying air pressure to a leading electrode. The application of air pressure to the leading electrode temporarily inhibits movement of the leading electrode along the track. An air jet may be mounted near the vibratory track across from one of the inclining wall portions for applying pressure to misoriented electrodes. The application of air pressure to the misoriented electrodes assists in properly reorienting misoriented electrodes.
The apparatus may include an air jet mounted near one side of the vibratory track for applying air pressure to the vibratory track. A blow off tray is mounted near a second side of the vibratory track. The application of air pressure by the air jet to the vibratory track blows debris off the vibratory track into the blow off tray. The apparatus may include an air jet mounted near a first side of a vibratory track for applying air pressure to improperly oriented electrodes. An opening in the bowl is located near the second side of the vibratory track for accepting improperly oriented electrodes. A sensor may be located near a second end of the track for sensing the presence of an electrode tip. A movable stop may be included near the second end of the track for selectively allowing electrode tips to exit the second end of the track.
To transport and orient electrodes for assembly into a lamp, a supply of electrodes is provided to the vibratory track. A leading electrode having an elongated shank portion and an enlarged coil portion is separated from the supply of electrodes. The separated leading electrode is moved along the vibratory track. The shank portion of a misoriented leading electrode is engaged by the inclined wall portion of the vibratory track to reorient the misoriented electrode. The properly oriented leading electrode is moved along the vibratory track to transport the leading electrode to its destination.
The separation of a leading electrode may be accomplished by applying fluid pressure to the leading electrode to temporarily inhibit motion of the leading electrode along the track. Fluid pressure may be applied to the coil portion of a misoriented leading electrode to assist reorientation of the leading electrode. Fluid pressure may be applied to the track to remove debris from the track. Fluid pressure may be applied to misoriented leading electrode to return the misoriented electrode to the supply of electrode. The shank portion of a misoriented electrode that is not successfully reoriented by a first inclined wall portion may be engaged by one or more subsequent inclined wall portions of the track to reorient the misoriented electrode shank portion. The shank portion of a misoriented electrode may be engaged with a substantially vertical wall to reorient the misoriented electrode.